Vehicle steering system

Abstract

A steering system for a motor vehicle includes a steering handle for manual actuation of the steering system, at least one steerable motor vehicle wheel which can be mechanically coupled to the steering handle, and a steering column which is rotatable about a steering-system axis and has an input shaft connected fixedly to the steering handle and an output shaft connected to the at least one steerable motor vehicle wheel for rotation therewith. A steering-system-blocking element is connected fixedly to a body of the motor vehicle. A locking device can either enable or block a relative rotation between the input shaft and the body-mounted steering-system-blocking element. A coupling device can either enable or block a relative rotation between the input shaft and the output shaft.

What is claimed is: 
     
       1. A steering system for a vehicle equipped with a steering handle for manual actuation of the steering system, comprising:
 at least one steerable vehicle wheel which is mechanically coupleable to the steering handle; 
 a steering column which is rotatable about a steering system axis and has an input shaft connected fixedly to the steering handle and an output shaft which is coupleable to the input shaft and whose rotary movement produces a steering movement of the steerable vehicle wheel via a steering gearbox; 
 a steering system blocking element, which is connected fixedly to a body of the vehicle; 
 a locking device, which optionally enables or blocks a relative rotation between the input shaft and the steering system blocking element; and 
 a coupling device, which optionally enables or blocks a relative rotation between the input shaft and the output shaft. 
 
     
     
       2. The steering system according to  claim 1 , wherein
 the steering handle is arranged so as to be axially movable for the actuation of the locking device, 
 the locking device, in a first axial position of the steering handle, enables a relative rotation between the input shaft and the body-mounted steering system blocking element and, in a second axial position of the steering handle, blocks a relative rotation between the input shaft and the body-mounted steering system blocking element, and 
 the steering handle in the second axial position, has a shorter axial distance from the output shaft than in the first axial position. 
 
     
     
       3. The steering system according to  claim 1 , wherein the locking device is a jaw coupling. 
     
     
       4. The steering system according to  claim 2 , further comprising:
 a detent device, which axially fixes the steering handle in the first axial position and/or in the second axial position. 
 
     
     
       5. The steering system according to  claim 4 , wherein
 the detent device is an electromagnetically actuated detent device that selectively enables or blocks an axial displacement of the steering handle. 
 
     
     
       6. The steering system according to  claim 2 , further comprising:
 a spring element, which forces the steering handle into the first axial position. 
 
     
     
       7. The steering system according to  claim 2 , wherein
 the steering handle is movable between the first and second axial positions, and 
 a dead center device assumes an unstable position of equilibrium between the first and second axial positions of the steering handle and forces the steering handle into the first or second axial positions outside of the unstable position of equilibrium. 
 
     
     
       8. The steering system according to  claim 1 , wherein the coupling device is a jaw coupling. 
     
     
       9. The steering system according to  claim 8 , wherein
 the coupling device, in a first axial position of the steering handle, blocks a relative rotation between the input shaft and the output shaft and, in a second axial position of the steering handle, enables a relative rotation between the input shaft and the output shaft. 
 
     
     
       10. The steering system according to  claim 1 , wherein the coupling device is designed as a superposition gear. 
     
     
       11. The steering system according to  claim 1 , wherein
 the coupling device and the locking device are mechanically, electrically or electronically coupled together so that the coupling device assumes its enabled position in a blocked position of the locking device, and vice versa. 
 
     
     
       12. The steering system according to  claim 2 , wherein
 the vehicle has an electric motor adjustable driver's seat, 
 in the case of the second axial position of the steering handle, in which the steering handle has a shorter axial distance from the output shaft than in the first axial position, the driver's seat is moved into a position in which it is also further away from the output shaft, viewed axially, than in the first axial position of the steering handle. 
 
     
     
       13. The steering system according to  claim 1 , further comprising:
 an electronic control unit, which only enables an axial displacement of the steering handle toward the output shaft when the vehicle can move in a highly automated driving mode, and/or which automatically initiates an axial displacement of the steering handle away from the output shaft when an error monitoring system for the highly automated driving mode of the vehicle identifies a safety-relevant error. 
 
     
     
       14. The steering system according to  claim 2 , wherein
 the steering handle, in the second axial position, lies at least partially and at least approximately flush in a dashboard of the vehicle at a shorter axial distance from the output shaft, and 
 an indicator and/or operating unit for the driver is moved out of the dashboard when the steering handle lies at least partially and at least approximately flush in the dashboard.